Heat exchangers



1967 w. E. LlND ETAL 3,347,310

HEAT EXCHANGERS & m

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INVENTORS William E.-Lind BEIfT J. Mitchel! BY Maya Y ATTORNEYS Oct. 17,1967 w. E. LIND ETAL 0 HEAT EXCHANGERS Fi led Oct. 21, 1964 3Sheets-Sheet 2 INVENTORS Figs William E. Lind 8851 J. Mitchell BY Wm? 3Sheets-Sheet 5 INVENTORS lLmd William E.

6 Bart). Mitchell w. E. LIND ETAL HEAT EXCHANGERS Oct. 17, 1967 FiledOct. 21, 1964 United States Patent l 3,347,310 HEAT EXCHANGERS WilliamE. Lind and Bert J. Mitchell, Dallas, Tern, assignors to FrigikarCorporation, Dallas, Tern, a corporation of Texas Filed Get. 21, 1964,Ser. No. 405,380 Claims. (Cl. 165124) This invention relates to heatexchangers.

An object of this invention is to provide a new and improved heatexchanger through which airmay be circulated to transfer heat to or fromthe circulated air.

Another object is to provide a heat exchanger having parallel heatexchanger assemblies each having conduit means through which a heattransporting fluid may be circulated, the assemblies permitting flow ofair perpendicularly therethrough, whereby heat may be transferredbetween the air flowing therethrough and the heat transporting fluid.

Still another object is to provide a heat exchanger having means formoving air perpendicularly in one direction through middle portions ofthe two heat exchanger assemblies and simultaneously perpendicularly inthe opposite direction through outer end portions of the two assemblieswhereby air may be circulated through the heat exchanger inwardlythrough either the outer end portions of the two spaced assemblies andthen outwardly through the middle portions or inwardly through themiddle portions of the two assemblies and then outwardly through theouter end portions of the two assemblies. A further object is to providea heat exchanger wherein the rate of flow of air through the middleportions of the assemblies is different than the rate of flow of the airthrough the end portions whereby the rate of transfer of heat betweenthe air and the heat transporting fluid may be maintained substantiallyconstant at all portions of the assemblies.

A still further object is to provide a heat exchanger which may bemounted on a vehicle to permit air to flow therethrough due to themovement of the vehicle and which has means for circulating air throughthe heat exchanger when the vehicle is not moving or moving very slowly.

A still further object is to provide a heat exchanger mountable on avehicle whose air moving means, such as fans or blowers, are not causedto rotate or windmill due to the movement of air therepast when thevehicle is moving or due to wind blowing therepast when the vehicle isnot moving.

An important object of the invention is to provide a heat exchangerwhich may be used as the evaporator unit of a refrigerant system tomaintain a low temperature in a chamber, such as theinterior of a truck.

Still another object is to provide a chamber having a heat exchangermounted therein which provides proper circulation of the air throughoutall portions of the chamber whereby a predetermined substantiallyuniform temperaturemay be maintained in all portions of the chamber.

Additional objects and advantages of the invention will be readilyapparent from the reading of the following description of a deviceconstructed in accordance with the invention, and reference to theaccompanying drawings thereof, wherein:

FIGURE 1 is a side view, with some parts broken away, of a heatexchanger embodying the invention;

FIGURE 2 is a top view, with some parts broken away, of the heatexchanger;

FIGURE 3 is a sectional view taken on line 33 of FIGURE 1;

FIGURE 4- is a perspective view showing the heat exchanger mounted on avehicle;

3,3413% Patented Oct. 17, 1967 FIGURE 5 is a schematic verticalsectional illustration of the truck body having the heat exchangerembodying the invention installed therein for use as the evaporator unitof a refrigerant apparatus;

FIGURE 6 is a schematic sectional illustration taken on line 66 ofFIGURE 5; and

FIGURE 7 is a sectional view taken on line 7-7 of FIGURE 6.

Referring now to the drawings, a heat exchanger 10 embodying theinvention is shown in use as the condenser of a refrigerating apparatusemployed to cool and condense refrigerant gas compressed by a compressorof the apparatus prior to its transmission to another heat exchanger ofthe apparatus wherein the condensed refrigerant gas evaporates andexpands. The condenser 10 is mounted on the top of a truck or othervehicle V to permit air to circulate therethrough either due to themovement of the vehicle or due to the operation of the fan motor 12.

The condenser includes a base or support plate 14 having a plurality ofresilient suction cups 15, secured thereto by means of the screws 16, bymeans of which the condenser may be mounted on the vehicle. Thecondenser may also be secured to the vehicle by additional other meanssuch as straps, clamps and the like.

The condenser includes a front heat exchanger assembly 17 whose tubes orcoils 18 extend through suitable apertures in and are expanded to bondto the usual spaced vertical heat conductor fins 20. The coils 18 alsoextend through apertures in and are suitably mounted on vertical supportbrackets 22 and 23 of the assembly disposed on opposite ends of thefins. The coils 13a of the front row are connected in series and thecoils 18b of the rear or inner row are also connected in series. Thesupport brackets 22 and 23 have transversely outwardly extendingvertical flanges Z4 and 25, respectively, which extend downwardly withinthe front vertical flange 26 of the base 14 and are rigidly securedthereto in any suitable manner, as by the self tapping screws 28.

A similar rear heat exchanger assembly 29 includes a plurality of tubesor coils 3%) which extend through suitable apertures in and are expandedto bond to the usual heat conductor fins 31. Opposite ends of the tubes30 extend through suitable apertures in the transversely spaced supportbrackets 32 and 33. The front or inner tubes Site are connected inseries and the rear tubes 3% are similarly connected in series. Thesupport brackets 32 and 33 have vertical flanges 34 and 35,respectively, which extend inwardly of the vertical rear flange 35 ofthe base and are rigidly secured thereto by the screws 36.

Hot compressed refrigerant gas is conducted to the upper ends of the twotop tubes 36a and 3% of the rear heat exchanger assembly by an inletconduit 40 which extends through a suitable aperture 42 in the flange 34of the support bracket 32 and the cooled and condensed refrigerant gasis conducted from the two bottom tubes of the front heat exchangerassembly through the outlet conduit 43 which extends through a suitableaperture .5 in the flange 34. The bottom ends of the two bottom tubesSlla and 30b are connected to the two top tubes 18 of the front heatexchanger assembly by two connector conduits 47a and 47b. The tubes ofthe two heat exchanger assemblies, are thus connected in series. Therefrigerant gas which flows through the outer tubes 30b of the rear heatexchanger assembly thus flows to the top tube 181') and then through theinner tubes 18b of the front heat exchanger assembly while therefrigerant gas which flows through the inner tubes 30a of the rear heatexchanger assembly thus flows to the top tube 18a and then through theouter tubes 18a of the front heat exchanger assembly.

The usual pressure responsive control means 48 of the refrigeratingapparatus, which controls the operation of the fans, is rigidly securedto an angle support bracket 49 whose opposite ends are rigidly securedto the brackets 22 and 32 by the screws 51. The conduit 47a has a T-fitting 52 connected therein by means of which the pressure of the gasin the coils is communicated through a suitable fitting 53 to thepressure responsive control means.

It will be apparent that the refrigerant gas compressed by the usualcompressor of the apparatus in flowing through the coils of the rear andfront heat exchanger assemblies is cooled and condensed and the flows tothe usual reservoir of the refrigerating appartus from which it may beconducted to the evaporator coils of another heat exchanger wherein thecondensed refrigerant gas is allowed to evaporate and expand to cool achamber of the vehicle in which such other heat exchanger is located.

The fins of the front heat exchanger assembly are protected againstdamage by a grill 55 formed of suitable wires, which are welded orotherwise secured to one another. The lower end portion of the grillextends between the fins 20 and the front flange 26 of the base and itsupper rearwardly extending upper end portion 56 extends over the upperends of the fins. The rear heat exchanger assembly is similarlyprotected by a grill 58 Whose lower end portion extends inwardly of thevertical rear flange of the base and whose upper end portion 59 extendsforwardly over the upper ends of the fins 31. If desired, at least thelowermost bottom horizontal wires of the grills may be provided withhook ends 59a which hook or extend about the flanges or the adjacentsupport brackets of the support assemblies to prevent transversemovement of the grills.

A cover 60 extends over the heat exchanger assemblies and includes a tophorizontal wall 61 which rests on the resilient insulator pads or strips62 and 63 disposed on the upper inner portions of the fins 20 and 30,respectively, inwardly of the top end portions 56' and 59 of theprotector grills. The cover also has side walls 66 and 67 whichtelescope over the vertical side flanges 69 and 70 of the base and arerigidly secured thereto by screws 72.

The space between the forward and rear heat exchangers assemblies andbetween the cover cooperating therewith and the base is divided intothree passages 75, 76 and 77 by a pair of orifice plates 78 and 79. Eachof the orifice plates has a horizontal bottom flange 80 which rests uponand is rigidly seured by screws 81 to the base plate 14, and front andrear vertical flanges 82 and 83 which abut the inner sides of the fins20 and 30, respectively, of the two heat exchanger assemblies. The tophorizontal flanges 85 of the orifice plates are rigidly secured to thetop wall 61 by means of screws 89 which extend through suitableapertures in the cover into suitable nuts 90 rigidly secured to the topflanges. Suitable insulator pads or gaskets 91 may be interposed betweenthe top flanges and the inner surface of the horizontal wall 61 of thecover.

The orifice plates 78 and '79 have apertures or orifices 93 and 94,respectively, in which are rotatably disposed the fans 96 and 97 rigidlysecured to opposite ends of the drive shaft 99 of the blower motor 12.

The motor is rigidly mounted on the base by a pair of mount brackets 101and 102 whose horizontal flanges 103 and 104, respectively, are rigidlysecured to the base plate by means of bolts 105 which extend throughsuitable slots 106 in the horizontal flanges and suitable apertures inthe base. The motor is disposed between and secured to the mountbrackets by means of suitable bolts 107. Suitable washers 110 and/ orrubber mounts may be interposed between the mount brackets and themotor. The drive shaft 99 extends through suitable upwardly openingslots 111 provided in the mount brackets.

The blades of the fans 97 and 96 are of opposite pitch so that when thedrive shaft revolves in a counter-clockwise direction, FIGURE 3, air ismoved from the end passage 75 through the orifice 93 of the orificeplate 78 by the fan 96 into the middle passage 76 and simultaneously airis moved by the fan 97 from the other end passage 77 through the orifice94 into the middle passage 76. As a result, during the operation of themotor, air is drawn inwardly through the outer end portions of both thefront and rear heat exchanger assemblies into the end passages 75 and77, thence through the orifices 93 and 94 of the orifice plates into themiddle passage 76 and then forwardly and rearwardly from the middlepassage through the middle portions of the forward and rear heatexchanger assemblies. During the passage of the air through the heatexchanger assemblies it absorbs heat from the coil and the fins thereofand therefor from the hot refrigerant gas flowing through the coils.

If the passages 75, 76 and 77 are of the same lengths, as illustrated inthe drawings, the air moves outwardly from the middle passage throughthe middle portions of the forward and rear heat exchanger assemblies attwice the rate as it is moved through the outer end portions of the heatexchanger assemblies into the end passages since the air moved by boththe fans must flow outwardly through the middle portions. Thisdifference in the rate or volume per unit of time of flow of air throughthe outer end portions and the middle portions of the heat exchangerassemblies increases the efficiency of the heat exchanger since thetemperature of the air flowing through the outer end portions of thecoil assemblies into the end passages 75 and 77 increases as it absorbsheat from the hot refrigerant gas in the coils and the air flowingoutwardly from the middle passage through the middle portions of theheat exchanger assemblies is therefore of a higher temperature. Theincreased rate of flow of air through the middle portions of the heatexchanger assemblies thus compensates for its higher temperature andensures proper transfer of heat from the refrigerant gas to the air, itbeing apparent that the rate of transfer of heat varies not only withthe difference in the temperatures of the air and the refrigerant gasbut also with the volume of air per unit of time moving through themiddle and end portions of the heat exchanger assemblies.

In use, the motor, which may be controlled by a suitable switch isoperated only when the truck is moving very slowly or is stationary.When the vehicle is traveling at a normal speed, the ram effect of theair causes it to flow directly rearwardly through the forward heatexchanger assembly, through the three passages, and then through therear heat exchanger in assembly. The air absorbs heat from therefrigerant gas in passing through the coils. The refrigerant gas in therear coils of the rear assembly is, of course, at a higher temperaturethan the refrigerant gas flowing through the coils of the frontassembly.

The blades of the fans 96 and 97 being of opposite pitch, even innumber, for example, four, and rotatable about an axis which isperpendicular to the direction of flow of air through the passagesduring the normal movement of the vehicle, such ram flow of airtherepast does not cause the fans to rotate thus minimizing wear of thebearings which support the drive shaft. The opposed pitch of the bladesof the two fans balances the longitudinal thrust on the drive shaft andtherefore on the bearings which support the drive shaft during therotation of the drive shaft.

In use, when the vehicle is stationary and the refrigerating apparatusis in operation, the motor 12 is connected to the battery of the vehicleby a suitable switch means in order to circulate the air through theheat exchanger assemblies in the manner described to cause the hotcompressed refrigerant gas flowing through the coils of the heatexchanger assemblies to cool and condense. If the vehicle is travelingat such speed that the rate of flow of air through the front heatexchanger assembly, the passages 75, 76, and 77 and then therear'exchanger assembly, is sufliciently great to cool and condense the:

refrigerant gas flowing through the coils of the heat exchangerassemblies, the motor 12 is not energized. During this normal operationof the heat exchanger when the motor 12 is not in operation, the airflows through all portions of the front heat exchanger assembly into thepassages, and during its passage through the front heat exchanger unitits temperature is increased due to the absorption of heat from therefrigerant gas in the coils 18 so that this air flowing through therear heat exchanger assembly is at a higher temperature than the airflowing through the front heat exchanger unit. However, the temperatureof the refrigerant gas in the coils 30 is higher than the temperature ofthe refrigerant gas flowing through the coils 18 and therefore thetemperature differential between the air flowing through the front heatexchanger and the refrigerant gas in the coils 3t) and thus both heatexchanger assemblies tend to transfer substantially equal amounts ofheat from the refrigerant gas to the air.

It will now be seen that the heat exchanger embodying the inventionincludes a front heat exchanger means through which air is movable toabsorb heat from a fluid flowing through the coils 18 of the front heatexchanger means or assembly 17, a rear heat exchanger assembly 29 spacedrearwardly of the front heat exchanger means, through which air ismovable to absorb heat from fluid flowing through its coils 30, meanssuch as the cover 60, the base 14 and the two orifice plates 78 and 79,defining the space between the two heat exchanger means into threepassages, and an air moving means, such as the fans 96 and 97, formoving air between the middle passage and the end passages when the airmoving means is in operation and therefore through end and middleportions of the two heat exchanger means.

It will further be seen that during the travel of the vehicle atrelatively high speeds, the air which moves through the front heatexchanger unit is warmed by the absorption of heat from the refrigerantgas circulating therethrough and then flows through the rear heatexchanger unit and that the two heat exchanger assemblies thus functionas a single unit but since the volume of the air flowing therethroughper unit of time is relatively great, the required cooling of therefrigerant gas easily takes place It will further be seen that when theair is being circulated through the heat exchanger by the operation ofthe fans, the two heat exchanger assemblies in effect operate asseparate units with fresh air being circulated through each heatexchanger assembly without also being circulated through the other sothat the air flowing through either heat exchanger assembly has not beenpreviously warmed by flowing through the other whereby the requiredcooling of the refrigerant gas flowing through the heat exchangerassemblies takes place even though the volume of air flowing througheach assembly per unit of time may be considerably smaller than when thevehicle is traveling at a normal speed over the highway and ram flow ofair is taking place through the heat exchanger assembly.

It will further be seen that while particular connections have beenillustrated and described between the tubes of the two heat exchangerassemblies to provide a particular pattern of circulation of the hotrefrigerant gas therethrough, that different patterns of circulation ofthe refrigerant gas through these tubes may be provided as required ormade desirable by particular installation. For example, the two rows oftubes of each heat exchanger assembly may be connected in series,instead of in parallel as illustrated and described, for series flow ofthe refrigerant gas therethrough, it being preferable, however, wheneverthe heat exchanger is used as the condenser of a refrigerationapparatus, that the hot refrigerant gas be circulated first through thetubes of the rear heat exchanger assembly before being circulatedthrough the tubes of the front heat exchanger assembly ti in order thata substantially uniform heat differential be maintained between the airflowing through the two heat exchanger assemblies and the hotrefrigerant gas being circulated therethrough.

Referring now to FIGURES 5, 6 and 7 of the drawings the heat exchanger1061 which is shown in use as the evaporator unit of a refrigerationapparatus to cool the interior or chamber 2'00 of a truck 201, issimilar to the heat exchanger 10, and accordingly, its elements havebeen provided with the same reference numerals, to which the subscript ahas been added, as the corresponding elements of the heat exchanger 10.The heat exchanger ltla is secured to the top wall or roof 204 of thetruck body by means of a pair of support angle members 205 and 206 whosevertical flanges are secured to the vertical flanges 26a and 35a of thesupport plate 14a by means of bolts or screws 28a and 36a, respectively.The horizontal flanges of the angle members, whose top surfaces abut thebottom surface of the roof of the truck, are rigidly secured to the roofin any suitable manner, as by bolts 208.

The horizontal wall 61a of the cover 60a of the heat exchanger isprovided with upwardly extending vertical flanges 265 and 210 whichextend between the vertical side walls 66a and 67a of the cover. Theinsulator pads or gaskets 91a, which are interposed between thehorizontal cover wall 61a and the horizontal flanges 85a of the orificeplates 78 and 79 may be provided with apertures or passages 212 throughwhich the condensate draining off the tubes may flow to a condensateduct, connected to the horizontal cover wall 61a, which opens to asuitable aperture 215 of the horizontal wall. The condensate drain tubeor conduit 214 may lie close to the horizontal wall 61a, its spacingtherefrom being exaggerated in the drawings, in order that it not takeup unnecessary space and that it not be exposed to physical damage,

Cooled liquified refrigerant gas is supplied to the tubes 18 and 30 ofthe two heat exchanger assemblies 17a and 2%, respectively, through theconduit. 40a which may extend from the condenser of the refrigeratorapparatus to the interior of the truck through a suitable aperture in awall of the truck while the war-med and evaporated refrigerant gas afterpassing through the tubes flows to the compresser of the refrigerationapparatus through the conduit 43a which may also extend to the exteriorof the truck through a suitable aperture in the truck wall. It will beappreciated that it is preferable that the refrigerant gas be conductedto the bottom tubes of the two heat exchanger assemblies through theconduit ttla which is connected to an end of each one of the tubes ofthe heat exchanger assemblies and that the refrigerant gas conduit 43abe connected to the other ends of the tubes of the two heat exchangerassemblies so that the tubes of the two assemblies are in effectconnected in parallel between the two conduits 40a and 43a and the gasfiowing through, for example, the tubes 18 of one heat exchangerassembly does not flow through the tubes 30 of the other assembly andvice versa.

The heat exchanger ltla preferably extends substantially the length ofthe chamber 290 of the truck and occupies a very small cubic volumethereof. When the fans 96a and 97a are in operation, the air is drawninwardly through the outer end portions of the two heat exchangerassemblies and into the end passages a and 77a, then through theorifices of the orifice plates 78a and 7% into the middle passage 76aand then outwardly in opposite directions through the middle portions ofthe two heat exchanger assemblies. It will be apparent that an effectivecirculation of the air throughout the chamber is obtained 'by theoperation of the heat exchanger like since the cooled air as it flowslaterally outwardly from the middle passage 76a, because it is now cold,tends to flow not only outwardly but also downwardly and the warm airwhich rises to the top of the truck is drawn in through both sides ofthe end passages 75a and 77a. Such uniform circulation of the airthroughout the chamber 2&0 tends to maintain the temperature through allportions of the chamber substantially uniform.

It will further be seen that the heat exchanger may be used as acondenser to cause heat to be transferred from a refrigerant fluidflowing through the coils of the two exchanger assemblies to the airflowing therethrough, and also to cause heat to be transferred from theair flowing through the exchanger unit to a refrigerant fluid flowingthrough the coils of the two heat exchanger assemblies, whereby the heatexchanger may be employed as the evaporator unit of a refrigerantapparatus to cool air such as in a food compartment or chamber of atruck.

It will further be seen that the pitch of the blades of the two fanscould be reversed so that upon rotation of the drive shaft, air would bemoved inwardly into the middle passage 76 through the middle portions ofthe two heat exchanger assemblies, into the end passages 75 and 77, andthence outwardly through the outer end portions of the two heatexchanger assemblies. This reverse flow may be desired where the heatexchanger 10 is used to cool air being moved therethrough in order toprovide a better circulation or distribution of the air in closedchamber such as a truck cab or the load compartment of a truck. In thiscase, the transverse length of the middle passage would be madepreferably twice as long as the length of the two end passages 75 and 77in order that the rate of flow of air through each outer end portion ofeach heat exchanger assembly be twice as great as' the flow of air intothe middle passage through its middle portion since the air flowingoutwardly from the outer end passages would, of course, be of a lowertemperature than the air flowing into the middle passage through themiddle portions of the heat exchanger assemblies.

It will further be seen that while the three passages 75, 76 and 77 ofthe heat exchanger have been described and illustrated as having lengthsof particular ratios or relationship, that the relative lengths of thesepassages may be varied as made desirable by the particular circulationor heat exchanger requirements of different installations.

It will further be seen that while the two fans have been shown as beingdriven by a single motor, if desired, separate motors may be employed todrive the fans or air moving means which may be especially desirable ifthe middle passage is of considerable length.

It will further be seen that the flow of the refrigerant gas through theheat exchanger, whether it is used as the condenser or the evaporator ofa refrigeration apparatus, and the operation of the fan motor may becontrolled either by manually operable switches or by suitable automaticcontrol devices, such as pressure or temperature responsive switcheswell known in the art.

It will also be seen that while the heat exchanger assemblies 17, 17a,29 and 29a have been illustrated as including two vertical rows of tubesthrough which the refrigerant gas is circulated, each of such assembliescould have only a single row of tubes or two or more rows.

The foregoing descripteon of the invention is explanatory only, andchanges in the details of the construction illustrated may be made bythose skilled in the art, Within the scope of the appended claims,without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A heat exchanger including: a pair of parallel vertical spaced heatexchanger assemblies providing an elongate space therebetween saidassemblies permitting flow of air perpendicularly therethrough betweensaid space and the exterior thereof; means cooperating with saidassemblies closing said space to prevent air flow into and from saidspace except through said assemblies; dividing means extendingperpendicularly to and between said assemblies dividing said space intoa middle passage and a pair of end passages, said dividing means havingapertures permitting air flow between said middle passage and said endpassages parallel to said assemblies; and means for moving air betweensaid middle passage and said end passages through said apertures.

2. The heat exchanger including: a pair of parallel vertical heatexchanger assemblies providing an elongate space there-between, each ofsaid assemblies including tubular means extending substantially thelength of said assemblies through which a heat transporting fluid mayflow, said assemblies permitting flow of air perpendicularlytherethrough between said space and the exterior thereof; meanscooperating with said assemblies closing said space to prevent air flowinto and from said space except through said heat exchanger assemblies;a pair of spaced plates extending between and perpendicular to saidassemblies and dividing said space into a middle passage and a pair ofend passages, said plates having apertures permitting fluid flow betweensaid middle passage and said end passages parallel to said assemblies;and air moving means disposed in said apertures and movablesimultaneously for moving air between said middle passage and said endpassages through said orifices.

3. A heat exchanger including: a pair of parallel vertical heatexchanger assemblies providing an elongate space therebetwe en; meanscooperating with said assemblies and closing said space at its top,bottom and ends to prevent air fiow into and from said space exceptthrough said heat exchanger assemblies; dividing means extendingperpendicular to and between said assemblies and dividing said spaceinto a middle passage and a pair of end passages, air being movablebetween said end passages and the exterior of said heat exchangerthrough outer end portions of said assemblies and being movable betweensaid middle passage and the exterior through middle portions of saidassemblies, said dividing means having apertures permitting fluid flowbetween said middle passage and said end passages parallel to saidassemblies; and means for moving air between said middle passage andsaid end passages through said apertures whereby when said air movingmeans is in operation air is moved through said outer end portions ofsaid assemblies inwardly into said end passages and outwardly from saidmiddle passage through said middle portions of said assemblies.

4. A heat exchanger including: a pair of parallel vertical heatexchanger assemblies providing an elongate space therebetween, each ofsaid assemblies including tubular means extending substantially thelength of said assemblies through which a heat transporting fluid mayflow, said assemblies permitting flow of air therethrough between saidspace and the exterior thereof; means cooperating with said assembliesand closing said space to prevent air flow into and from said spaceexcept through said heat exchanger assemblies; a pair of spaced platesextending between and perpendicular to said assemblies and dividing saidspace into a middle passage and a pair of end passages, said plateshaving apertures permitting fluid flow between said middle passage andsaid end passages parallel to said assemblies; means for moving airthrough said apertures; and means for simultaneously driving said movingmeans.

5. A heat exchanger including: a pair of parallel vertical heatexchanger assemblies providing an elongate space therebetween; meanscooperating with said assemblies closing said space at its top, bottomand ends to prevent air flow into and from said space except throughsaid heat exchanger assemblies; dividing means extending perpendicularto and between said assemblies and dividing said space into a middlepassage and a pair of end passages, air being movable between said endpassages and the exterior of said heat exchanger through outer endportions of said assemblies and being movable between said middlepassage and the exterior through middle portions of said assemblies,said dividing means having apertures permitting fluid flow between saidmiddle passage and said end passages parallel to said assemblies; adrive means mounted in said middle passage and having a rotatable driveshaft; and air moving means driven by said drive means for moving airthrough said apertures from said end passages into said middle passage.

6. A heat exchanger mountable on the exterior of a vehicle in exposedposition wherein movement of the vehicle causes ram flow of air throughsaid heat exchanger, said heat exchanger including: an elongate base;front and rear longitudinally extending transversely spaced parallelvertical heat exchanger assemblies mounted on said base, said heatexchanger assemblies extending transversely to the direction of movementof a vehicle when the heat exchanger is mounted thereon; a coverdisposed over the tops of said assemblies defining with said base andsaid assemblies a longitudinally extending space; air flowing throughsaid front assembly into said space and from said space rearwardly tothe exterior of said heat exchanger through said rear assembly when thevehicle is in motion; a pair of orifice plates in said space betweensaid bottom and cover and between said assemblies dividing said spaceinto a middle passage and a pair of end passages, said passages beingaligned longitudinally, air being movable between said middle passageand the exterior of the heat exchanger through middle portions of saidassemblies between said orifice plates and being movable between each ofsaid end passages and the exterior of the heat exchanger through outerend portions of said assemblies extending longitudinally outwardly ofits adjacent orifice plate, said orifice plates having orificescommunicating said middle passage with said end passages; drive means insaid middle passage; and air moving means driven by said drive means forsimultaneously moving air between said middle passage and each of saidend passages through said orifices.

7. The heat exchanger of claim 8 wherein said air moving means comprisefans operatively associated with said orifices rotatable about alongitudinal horizontal axis extending transverse to the direction ofmovement of a vehicle when the exchanger is mounted on the vehicle bysaid drive means for moving air into said middle passage from said endpassages through said orifices.

8. A heat exchanger mounted in a chamber to a top wall defining the topof a chamber, said heat exchanger including: a pair of parallel verticalspaced heat exchanger assemblies providing an elongate spacetherebetween, said assemblies permitting air fiow perpendicularlytherethrough between said space and exterior thereof; means cooperatingwith said assemblies closing said space to prevent air flow into andfrom said space except through said assemblies; means extendingperpendicularly to and between said assemblies dividing said space intoa middle passage and a pair of end passages, said dividing means havingapertures providing air flow between said middle passage and said endpassages; and means for moving air between said middle passage and saidend passages through said apertures whereby when said air moving meansis in operation air is simultaneously moved inwardly into one of saidmiddle passage and said end passages through certain portions of saidheat exchanger assemblies and outwardly from the other of said middlepassage and said end passages through other portions of said heatexchanger assemblie.

9. A heat exchanger mountable in a chamber to a top wall defining thetop of the chamber, said heat exchanger including: a pair of elongateparallel spaced heat exchanger assemblies providing an elongate spacetherebetween and extending substantially one full dimension of saidchamber, said assemblies permitting flow of air therethrough betweensaid space and the exterior thereof perpendicularly to said onedimension; means cooperating with said assemblies closing said space toprevent air flow into and from said space except through saidassemblies; means extending perpendicularly to and between saidassemblies dividing said space into a middle passage and a pair of endpassages; said dividing means having apertures providing for air flowbetween said middle passage and said end passages parallel to saidassemblies; and means for moving air between said middle pasage and saidend passages through said apertures.

10. The heat exchanger of claim '7, wherein each of said assembliesincludes tubular means extending substantially the length of saidassemblies through which a heat transporting fluid may flow, saidtubular means of said front and rear assemblies being connected to causeheat conducting fluid to flow first through the tubular means of saidrear assembly and then through the tubular means of said front assembly.

References Cited UNITED STATES PATENTS 1,877,905 9/1932 Le Grand -1222,029,368 2/1936 Goldwaite 165-121 2,184,837 12/1939 Hemming 165-4222,447,278 8/1948 Roper 62-259 2,977,774 4/1961 Ferris 62-212 2,995,9068/1961 Brandimarte 165124 3,163,995 1/1965 Maier 165-44 ROBERT A.OLEARY, Primary Examiner. T. W. Assistant Examiner,

1. A HEAT EXCHANGER INCLUDING: A PAIR OF PARALLEL VERTICAL SPACED HEATEXCHANGER ASSEMBLIES PROVIDING AN ELONGATE SPACE THEREBETWEEN SAIDASSEMBLIES PERMITTING FLOW OF AIR PERPENDICULARLY THERETHROUGH BETWEENSAID SPACE AND THE EXTERIOR THEREOF; MEANS COOPERATING WITH SAIDASSEMBLIES CLOSING SAID SPACE TO PREVENT AIR FLOW INTO AND FROM SAIDSPACE EXCEPT THROUGH SAID ASSEMBLIES; DIVIDING MEANS EXTENDINGPERPENDICULARLY TO AND BETWEEN SAID ASSEMBLIES DIVIDING SAID SPACE INTOA MIDDLE PASSAGE AND A PAIR OF END PASSAGES, SAID DIVIDING MEANS HAVINGA PERTURES PERMITTING AIR FLOW BETWEEN SAID MIDDLE PASSAGE AND SAID ENDPASSAGES PARALLEL TO SAID ASSEMBLIES; AND MEANS FOR MOVING AIR BETWEENSAID MIDDLE PASSAGE AND SAID END PASSAGES THROUGH SAID APERTURES.